(from Retiring Guy's postcard collection)
Source: Madison (WI) City Directory 1941
In 1927, 37% of U.S. households had telephone service. This number fell to 31% by 1932, (1933 is generally considered the year when economic conditions during the Great Depression were at their worst.) By 1940, 35% of U.S. households had telephone service. It would be another year before the percentage of telephone households matched the 1927 number.
From the Telephony Museum's webpage on telephone history. Of course, everything was up for grabs when the depression hit. During a two year period in the early 1930s, telephones in service declined by 10% across the nation and Western Electric laid off 85% of its work force. The only thing keeping Western from an almost total lay off was its conversion of manual telephones to dial.
Then there's this bit of wholesale history from AT&T at "130 Years of the Telephone - A Brief History of the Telephone and Information Transmission". 1930s The first colored phones were introduced. The painted finishes were offered in gray, ivory, oxidized silver, statuary bronze and old brass.
Retiring Guy takes a look back. The conversion to manual phones didn't take place in Warren PA until 1958. I remember it well. Until I was 8 years old, our only telephone, black in color, didn't have a dial. When I picked up the heavy receiver, an operator chirped, "Number, please." The response time seemed to lengthen and the level of courtesy decrease as the conversion date approached.
Column graph 1: Postal receipts. (12/11/2013)
Column graph 2: Gas meters. (12/12/2013)